0000000000134525
AUTHOR
Marek Nowak
Structural characterization and electrochemical hydrogen storage properties of Ti2LxZrxNi (x [ 0, 0.1, 0.2) alloys prepared by mechanical alloying
International audience; Nominal Ti2Ni was synthesized under argon atmosphere at room temperature using a planetary high-energy ball mill. The effect of milling time and Zr substitution for Ti on the microstructure was characterized by XRD, SEM and TEM, and the discharge capacities of Ti2xZrxNi (x 1/4 0, 0.1, 0.2) were examined by electrochemical measurements at galvanostatic conditions. XRD analysis shows that amorphous phase of Ti2Ni can be elaborated by 60 h of milling, whereas Zr substitution hinders amorphization process of the system. The products of ball milling nominal Ti2xZrxNi (x 1/4 0.1, 0.2) were austenitic (Ti, Zr)Ni and partly TiO, despite the fact that the operation was carrie…
Synergistic effects of multiwalled carbon nanotubes and Al on the electrochemical hydrogen storage properties of Mg2Ni-type alloy prepared by mechanical alloying
Abstract Mg 2− x Al x Ni ( x = 0, 0.25) electrode alloys with and without multiwalled carbon nanotubes (MWCNTs) have been prepared by mechanical alloying (MA) under argon atmosphere at room temperature using a planetary high-energy ball mill. The microstructures of synthesized alloys are characterized by XRD, SEM and TEM. XRD analysis results indicate that Al substitution results in the formation of AlNi-type solid solution that can interstitially dissolve hydrogen atoms. In contrast, the addition of MWCNTs hardly affects the XRD patterns. SEM observations show that after co-milling with 5 wt. % MWCNTs, the particle sizes of both Mg 2 Ni and Mg 1.75 Al 0.25 Ni milled alloys are decreased e…
Mg2-xTixNi (x=0, 0.5) alloys prepared by mechanical alloying for electrochemical hydrogen storage: Experiments and first-principles calculations
International audience; Mg2-xTixNi (x = 0, 0.5) electrode alloys have been prepared by mechanical alloying (MA) under argon atmosphere at room temperature using a planetary high-energy ball mill. The microstructures of synthesized alloys are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The effects of substitutional doping of Ti in Mg2Ni phase have been investigated by first-principles density functional theory calculations. XRD analysis results indicate that Ti substitution for Mg in Mg2Ni-type alloys results in the formation of TiNi (Pm-3m) and TiNi3 intermetallics. With the increase of milling time, the TiNi phase…